This invention relates to a remote controlled helicopter and more particularly to an improved arrangement for controlling the flight path of such a helicopter.
Radio controlled aircraft have been popular for recreational purposes for a number of years. Such aircraft include radio controlled helicopters. Recently, however, it has been realized that radio controlled, pilotless helicopters may be used for a wide variety of functional purposes. For example, the use of such radio controlled helicopters for agricultural purposes such as crop spraying has been found to be a very practical purpose. By employing radio controlled helicopters for this use, it is possible to spray relatively large crop areas without having the sprayed chemical travel to areas where spraying is not required. This is possible because the radio controlled helicopter can be operated at a very low altitude close to the ground without danger. However, normal radio controlled helicopters do present certain difficulties in that, when the area to be sprayed is quite large, the accuracy of the control may become a problem.
It is, therefore, a principal object of this invention to provide an improved control arrangement for a radio controlled helicopter.
It is a further object of this invention to provide a control for a radio controlled helicopter wherein at least a portion of the control functions for the helicopter are positively limited.
It has been discovered that the control of a radio control helicopter can be improved if a tether or cable is connected between the fuselage of the helicopter and a fixed point on the ground. By the use of such a tether control, the range of the helicopter can be positively controlled and the radio control function need only apply to the height and lateral position. As a result, improved control is provided without sacrificing the other advantages of radio control. It has been discovered, however, that the point of attachment to the fuselage can be critical in such arrangements.
It is, therefore, a still further object of the invention to provide an improved tether control for a radio controlled helicopter.
As is well known, a helicopter normally includes a main rotor that rotates about a vertically extending axis and is operative to control the height and speed of forward travel of the machine. In addition, there is normally incorporated a tail rotor that operates to provide a counter torque acting against the torque caused by the main rotor which tends to cause the fuselage to rotate about the same axis as the main rotor. It has been found that by appropriately locating the tether control for the helicopter the size of the tail rotor may be reduced or, in fact, the tail rotor may be completely eliminated.
It is, therefore, a still further object of this invention to provide an improved tether control for a radio controlled helicopter that permits reduction in the size or elimination of the tail rotor.